The present invention relates to seating units having a seat support and back coupled to a base for synchronous movement and having an energy device biasing the seat support and back to upright positions.
Synchrotilt chairs provide a seat that moves simultaneously with recline of its back, such as to reduce “shirt pull” upon recline, to improve comfort, and to promote healthier support when performing tasks while seated for extended periods of time. In one type of synchrotilt chair, the seat moves forward upon recline of its back, so that a seated user's hands stay relatively stationary whether the back is in the upright or reclined position. This is not easily accomplished, since it requires a mechanism that creates stable and smooth forward movement of the seat during rearward recline of the back. Also, it is desirable to reduce cost, weight, and assembly time, and to accomplish this with simplified components. At the same time, the competitive furniture market requires high quality and durability. There are many conflicting and challenging design requirements, such as the desire for small package size, while maintaining an attractive appearance, an environmental “green” friendliness (including the ability to separate components into recyclable parts without substantial effort), and a desire for design flexibility, relatively few components, and mechanically-efficient arrangements that are durable, long-lasting, robust, and easily assembled.
One prior art chair disclosed in Battey et al. U.S. Pat. No. 5,871,258 (and several related patents) includes a seat and a back operably supported for synchronous movement between upright and reclined positions, with the seat moving forwardly upon recline of the back. The energy mechanism in this patent disclosure is of interest (and is claimed primarily in related U.S. Pat. No. 6,086,153); the seat is of interest (and is claimed primarily in U.S. Pat. No. 5,871,258 and also see related U.S. Pat. Nos. 5,909,923 and 5,979,984); and the back is of interest (and is initially claimed in U.S. Pat. No. 5,975,634 but also see several subsequent applications continued from U.S. Pat. No. 6,086,153). However, improvements are desired in the chair disclosed in Battey '258 (and related patents) to simplify components, reduce parts and pieces, make them lower in weight and cost, improve assembly and reduce manual labor during assembly, and to make the assembly more durable and robust.
Thus, a system having the aforementioned advantages and solving the aforementioned problems is desired.